P024

DTC PO24:

PCM Circuit:

DESCRIPTION
The Powertrain Control Module (PCM) receives unbuffered speed information from the Vehicle Speed Sensor(VSS) located in the transaxle assembly. If the PCM detects 0 MPH when the engine RPM and Throttle Position (TP) sensor indicate that the vehicle is moving, Code P024 is set. To avoid any erratic cruise control operation due to an intermittent problem, the cruise control system is disabled for the entire ignition cycle.

TEST CONDITIONS
1. Codes P021, P022, P026 and P027 not set.
2. Transaxle in Drive or Reverse.
3. Brakes not applied.
4. Throttle position switch open.
5. Throttle angle 17.3 degrees or greater.
6. RPM 1400 or greater.

FAILURE CONDITIONS
Vehicle speed 0 mph for 3.3 seconds.

ACTION TAKEN
1. PCM turns "ON" the "Service Engine Soon" Malfunction Indicator Lamp (MIL).
2. PCM disables cruise control for entire ignition cycle.
3. PCM disables Torque Converter Clutch (TCC).
4. PCM disables third and fourth gears.

NOTES ON FAULT TREE
1. If Code PO24 is current, the fault is present and can be diagnosed directly. If PO24 is stored as history, use PO75 to diagnose because fault is intermittent.

2. The vehicle speed sensor will generate a frequency of greater than 0 Hertz when spun by hand. If it does, the PCM may be at fault. If it does not, check wires/sensor for opens and shorts.

NOTES ON INTERMITTENTS
Check for Electromagnetic Interference (EMI) induced on CKT's 400 and 401 by running them along side spark plug wires or high power transmitters (like mobile radios) operating in the vicinity.